废PET的醇解及其在不饱和聚酯树脂合成中的应用

Alcoholysis of waste PET and its application for the synthesis of unsaturated polyester resin

将采用甘油/二甘醇(DEG)混合醇为醇解剂,钛酸四丁酯为催化剂醇解废PET得到的醇解产物与顺酐、单元酸进行反应,制得不饱和聚酯树脂。通过红外光谱及粘度和力学性能测试等研究了醇解条件对PET醇解产物的影响及合成条件对不饱和聚酯树脂的性能影响。结果表明,n(甘油)∶n(DEG)=0.75∶1,n(混合醇)∶n(PET)=2∶1,钛酸四丁酯用量为PET质量的0.2%,醇解3 h条件下PET聚酯降解很彻底。n(顺酐)∶n(PET)=2∶1时顺丁烯二酸单辛酯封端甘油得到不饱和聚酯树脂的性能良好,该合成工艺简单、平稳可控,树脂色泽好、强度高、韧性好。

The alcoholysis products were obtained by alcoholysis of waste PET using glyceride / diethylene glycol （DEG） mixed alcohol as alcoholysis agent and tetrabutyl titanate as catalyst and then reacted with the maleic anhydride and monoacid to prepare unsaturated polyester resin. The effects of alcoholysis conditions on the alcoholysis products and the effect of the synthesis conditions on the properties of unsaturated polyester resin were investigated by infrared spectroscopy and the testings of viscosity and mechanical properties. The results showed that the degradation of PET was very thorough under the conditions as followed ： n（ glycerol ） ： n（DEG） = 0.75 ： 1 , n（ mixed alcohol ） ：n（ PET ） = 2 ： 1 , tetrabutyl titanate amount 0.2wt% of the PET and alcoholysis time 3 h. The properties of unsaturated polyester resin obtained by maleic acid monooctyl ester terminated glycerol were good when the molar ratio of maleic anhydride to PET was 2 ： 1. The synthesis process was simple, stable and controllable. The resin had light color, high strength good toughness.